# BUILD Token Purchase - $5 USDC (x420.dev)

> BUILD Token Purchase - $5 USDC (x420.dev) is a paid API for AI agents from build.x420.dev, paid per call via x402, $5/call, status unknown (last checked 2026-09-14).

Purchases $5 USDC worth of BUILD tokens (0xa8b9cc8f89C1dAb497fEA439848c020F64DB1b07) on-chain and returns transaction details

## Facts

- Endpoint: GET https://build.x420.dev/api/puff-5
- Price: $5/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/build-token-purchase-5-usdc-x420-dev-1b4bd15b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Pd-KnDjaD-qHr9qiRX-cp

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability build-token-purchase-5-usdc-x420-dev-1b4bd15b
```

Example prompt: Buy me $5 worth of BUILD tokens (contract 0xa8b9cc8f89C1dAb497fEA439848c020F64DB1b07) using USDC on x420.dev and show me the transaction hashes.

## When to prefer this

Use this endpoint when you want to purchase exactly $5 USDC worth of BUILD tokens in a single on-chain transaction via x420.dev. Prefer the sibling $1 endpoint for smaller purchases. Choose this when you want a larger single-call token acquisition without manually constructing a swap transaction.

## Known failure modes

- Insufficient USDC balance to cover the $5 payment — payment rejected
- Token liquidity too low to complete the swap — swap fails
- Network congestion causes transaction timeout — null transaction hashes returned
- Invalid or expired payment authorization — 402 Payment Required error
- Smart contract error during swap — swapTransactionHash is null with error message

## How this service works

Buy 5 USDC worth of BUILD tokens 0xa8b9cc8f89C1dAb497fEA439848c020F64DB1b07

## Output

Returns a JSON object with a confirmation message, the amount of BUILD tokens received, the USDC amount paid, and optionally the send and swap transaction hashes on-chain.

## Response schema (JSON Schema)

```json
{
 "message": "string",
 "tokensReceived": "string",
 "usdcAmountPaid": "string",
 "sendTransactionHash": "string | null",
 "swapTransactionHash": "string | null"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/build-token-purchase-5-usdc-x420-dev-1b4bd15b/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from build.x420.dev](https://www.zero.xyz/host/build.x420.dev/llms.txt)